WASHINGTON - Less than a week before annual U.S.-Chinese diplomatic and economic talks, relations between the powers risked sharp deterioration Saturday with an escaped Chinese activist reportedly under American protection and a U.S. fighter-jet sale to Taiwan now being considered.

Fellow activists say Chen Guangcheng, a blind lawyer who exposed forced abortions and sterilizations as part of China's one-child policy, fled house arrest a week ago and has sought protection at the U.S. Embassy in Beijing.

Neither the U.S. nor Chinese government has confirmed the reports, but the saga looks set to overshadow this coming week's Strategic and Economic Dialogue in the Chinese capital. Secretary of State Hillary Rodham Clinton and Treasury Secretary Timothy Geithner are leading the U.S. side at the talks beginning Thursday.

A potential further complication is a letter from the White House director of legislative affairs, Rob Nabors, to Sen. John Cornyn (R., Texas), explaining that the Obama administration would consider selling new U.S. warplanes to Taiwan. A sale would infuriate China, which considers the island nation an integral part of its state even after their split more than six decades ago.

Chen's status and the fighter jets represent the latest strains in Washington and Beijing's up-and-down relationship in recent years. President Obama has sought to "pivot" American military might and diplomatic energy toward Asia to improve America's standing in the region and check the expansion of Chinese power, and has achieved mixed results.

The two issues underscore the fundamental disconnect between the world's No. 1 and No. 2 economies, the top importer and exporter, and the biggest military and the fastest developing, on issues from human rights and Taiwan to currency policy and combating nuclear-armed North Korea and potentially nuclear-armed Iran.

A Texas-based activist group that has been active in promoting Chen's case said China and the United States were discussing his fate.

"Chen is under U.S. protection and high-level talks are currently under way between U.S. and Chinese officials regarding Chen's status," said a statement from the ChinaAid Association. It cited a source close to the situation.

The U.S. Embassy in Beijing declined comment. Chinese Vice Foreign Minister Cui Tiankai said he had no information on Chen's case.

The case is so sensitive that officials in Washington have been ordered not to say anything about it at all. That was underscored Friday and Saturday by the absolute refusal of the White House to speak out on the matter and the State Department pretending that nothing unusual was afoot.

The top U.S. diplomat for Asia, Assistant Secretary of State Kurt Campbell, originally was due in Beijing in the coming week, but he arrived early Sunday in the capital and did not speak to reporters. Earlier, department officials in Washington had ignored or declined to respond to questions about indications that Campbell had been dispatched earlier than planned ahead of the talks to smooth things over with the Chinese.

ChinaAid's founder, Bob Fu, said Chen's case was a benchmark for the United States and its human-rights image around the world.

In February, a former regional chief of police, Wang Lijun, visited a U.S. consulate to raise concerns about the murder of a British businessman and possible links to powerful Chinese politician Bo Xilai. Wang expressed interest in seeking asylum with the United States but was turned away, raising eyebrows among Republican lawmakers in the United States.

Chen's case has become an embarrassment for Beijing. Fu and Chinese-based activists say he slipped away from his intensely guarded home on the night of April 22. His wife and 6-year-old daughter are still there.

Chen recorded a video as a direct address to Premier Wen Jiabao, condemning the treatment of him and his family and accusing local Communist Party officials by name. Activists sent the video Friday to the overseas Chinese news site Boxun.com, which posted part of it on YouTube.

In 1989, Fang Lizhi, whose speeches inspired student protesters throughout the 1980s, fled with his wife to the U.S. Embassy after China's military crackdown on the pro-democracy movement. He was forced to stay there for 13 months before China eventually let the couple leave the country. Once China's leading astrophysicist, he died April 7 at age 76 in Tucson, Ariz., where in exile he was a physics professor at the University of Arizona.

Chen, 40, is widely admired by rights activists in China who last year publicized his case among ordinary Chinese and encouraged them to go to Dongshigu village and break the security cordon. Even Hollywood actor Christian Bale tried to visit but was roughed up by locals paid to keep outsiders away.

A self-taught lawyer blinded by fever in infancy, Chen served four years in prison for exposing forced abortions and sterilizations in his and surrounding villages. Since his release in September 2010, local officials confined him to his home. Amnesty International and other human-rights groups say he was abused over the last 18 months.